Double-ended ball point pen



Feb. 12, 1963 J. P. VOGEL DOUBLE-ENDED BALL POINT PEN Fild Oct. 12, 1959 States This invention relates to ballpoint pens and, more particularly, to a double-ended ballpoint pen having a pair of offset and interlocked ink tubes.

For several years writing utensils have been available which provide a written record in two colors. For example, colored lead pencils are presently available which provide red and blue writing at opposite ends of the same pencil body. The advantage of having two colors available from the same writing implement is well known in many applications of commerce and industry.

In recent years, the ballpoint pen has rapidly supplanted the pencil wherever a writing instrument is needed that does not require frequent sharpening and is not shortened with use, thereby maintaining its balance. The written line does not broaden as the point wears blunt and, further, such pens provide a permanent record without blotting or smudging. The ballpoint pen can be used to provide a permanent original with multiple copie through the use of carbon papers. Carbon copies have been difficult with conventional ink-pens.

As the use of ballpoint pens increases and has become more widespread, attempts have been made to provide pens in substantially all varieties as may be found in pencils. Accordingly, ballpoint inks have been compounded in all of the colors of the rainbow and it is now possible to write in virtually every imaginable color. The color of ink contained in a pen may be signalled by a plastic barrel of the same color as the ink. With such an arrangement, the color in the pen corresponds to the color of the pen barrel.

In order to complete the gamut of writing instruments that are available as ballpoint pens, attempts have been made to provide a double-ended ballpoint pen similar to the two color, double-ended pencil. In certain doubleended pens of the prior art, the ink barrels have been placed in a side-by-side relationship which resulted in a pen whose points were not coaxial, but were eccentrically located. Other pens, at the sacrifice of a portion of the ink supply, have shortened ink tubes which permit alignment of the pens coaxially, in an end to end arrangement of the ink tubes. Still other pens have placed the ink tubes side by side and bent the point assemblies to achieve coaxial alignment.

According to the present invention, a double-ended ballpoint pen is provided whose points are coaxial. The ink tube for each pen has a length greater than one-half of the over-all length of the entire pen assembly. The pens are easily fabricated and assembled without special alignment or tolerance problems. The ink tubes are provided with oifset portions which interlock when the pen is assembled to provide internal strength and rigidity. Further, each ink tube, including the interlocking portions is of the same shape so that all tubes can be made in the same die. When the pen is assembled, the ink tubes tend to wedge the plastic barrels in place.

Accordingly, it is an object of the present invention to provide a double-ended ballpoint pen whose points are coaxially aligned.

It is a further object of invention to provide a doubleended ballpoint pen having interlocking ink tubes.

It is a still further object of invention to provide a writing instrument having ballpoint pens at opposite ends, each providing a diiferent color ink, the barrel of each portion being the color of the inks.

It is still another object of invention to provide a writ- ICC ing instrument of the ballpoint pen type having two ballpoint pens in back-to-back relationship in correspondingly colored barrels resulting in an integral double-ended pen whose points are coaxially aligned.

It is yet another object of invention to provide an ink tube for a ballpoint pen which interlocks back-to-back with an identical ink tube to form a double-ended ballpoint pen having greater structurally rigidity and ink capacity than pens of the prior art.

It is an additional object of invention to provide a double-ended ballpoint pen having interlocking tubes provided with barbs for anchoring the tubes in the pen barrel.

The novel features which are believed to be characteristic of the invention, both as to its organization and method of operation together with further objects and advantages thereof, will be better understood from the following description considered in connection with the accompanying drawings in which several embodiments of the invention are illustrated by way of example. It is to be expressly understood, however, that the drawings are for the purpose of illustration and description only, and are not indicated as a definition of the limits of the invention.

FIGURE 1 is an isometric view of a double-ended ballpoint pen according to the present invention.

FIGURE 2 is a side sectional view of the pen of FIG- URE 1, taken along line 2-2 in the direction of the appended arrows.

FIGURE 3 is a side view of a point and ink tube assembly according to the present invention.

FIGURE 4 is a top view of the point and ink tube assembly of FIGURE 3, taken along line 44 in the direction of the appended arrows.

FIGURE 5 is a cross-sectional view of the pen of FIGURE 2 taken along line 5-5 in the direction of the appended arrows.

FIGURE 6 is a cross-sectional view of the pen of FIGURE 2 taken along line 6-6 in the direction of the appended arrows.

FIGURE 7 is a side view, partly broken, of a pen according to the present invention in a stage of assembly.

FIGURE 8 is a top sectional view of 'a portion of an ink tube modified for improved anchoring in a plastic barrel.

With reference now to FIGURE 1, there is shown a double-ended ballpoint pen according to the present invention. One of the pens is filled, for example, with a blue ink, and therefore, that half of the pen is preferably encased in a blue plastic barrel. The other of the pens is filled with a red ink and is encased in a red barrel, thereby providing a utility pen in two colors in which the color of the barrel denotes the color of the ink. A plastic cap, shown in outline, may be provided at each end to protect the point and may be of the same color as the barrel.

Turning now to FIGURE 2, which is a. sectional view of the pen of FIGURE 1, there is provided an illustration of the manner in which the ink tubes are aligned to provide a greater ink supply for each pen, optimum utilization of the barrel interior, and axial alignment of the points.

With reference also to FIGURES 3 and 4 which are a top and side view, respectively, there is shown a pen 10, which includes an ink tube 12 terminating at one end in -a ball point 14. A plastic barrel 16 encases the pen and is substantially cylindrical in shape. The interior of the plastic barrel is slightly stepped so that the diameter of the portion near the point of the pen closely approximates the diameter of the ink tube. A ridged portion or crimp 18 is providedin the ink tube 12 which engages the interior of the plastic barrel to anchor the tube in position, extending into the barrel wall. The rearward end of the ink tube 12 has a slight bend 20, to the side,

a flattened portion 22, substantially parallel to the forward portion and is bent back to continue coaxial with the forward portion :of the tube in a terminal, cylindrical portion 2 4. This modification of shape may best be described as an offset portion with a slight flattening of the tube in the offset portion. The length of the offset portion is equal to the length of the rearmost portion of the tube.

A second pen is constructed identically to the first pen 10 and includes the same componentparts. The corresponding parts have the same reference characters with prime afiixed. The flattened portion 22' is the same length as the remaining cylindrical portion 24 so that portions of the second pen '10 can engage portions of the first pen 10 in an overlapping back-to-back relationship.

In addition to providing a greater ink supply, the shaping of the ink tubes at the rearward ends, also serves to outwardly bias the tubes against the plastic barrels, tending to Wedge against the barrels in a relatively rigid configuration that will not slip and twist. Preferably, the double-ended pen of the present invention is of a convenient over-all length for balanced writing. Without the provision of the stepped, overlapping ink tubes, the ink supply of each pen might necessarily be substantially less, as for example, if the tubes were substantially coaxially in an end-to-end relationship.

Turning now to FIGURE 5, there may be seen a crosssectional view of the pen of FIGURE 2 in which the overlapping interlock relationship of the ink tubes is plainly seen. The second cylindrical portion 24 of the ink tube 12' of pen 10 is juxtaposed adjacent the flattened portion 22 of the ink tube 12 of pen 10 as is easily seen from the drawing. The tubes are wedged together somewhat, and, therefore, may exert force on the walls of the plastic barrel 16 which tend to keep the barrel from sliding relative to the pens and maintain the entire assembly in a fairly rigid state.

FIGURE 6 is a cross-sectional view of the pen of FIGURE 2, showing in detail how the ridged or crimped portion 18 of the ink tube 12 engages the interior of the barrel to anchor the pen assembly in place at the forward end of the barrel.

A portion of a partially assembled pen 10 according to the present invention may be seen in FIGURE 7. Though not completely shown, a plastic barrel 16 has been fully advanced over the ink tube 12 and point 14 of pen 10, and has engaged the cylindrical portion 24 of pen 10 with the flattened portion 22 of pen 10'. To complete the assembly of the pen, the plastic barrel 16 must next be moved to the left (as viewed in FIGURE 7) until it meets with barrel 16. When finally assembled, the pen will appear as in FIGURE 1, with the ends of the two plastic barrels in close abutment. Each point and ink tube is firmly anchored to the barrel near the point end by the crimped portion 18, 18. At the overlapping interlocked portions .of the flattened and cylindrical portions of the ink tubes, additional anchoring support is provided by the outward force exerted by the tuba.

Turning now to FIGURE 8, there is illustrated a slight modification to an ink tube such :as is shown of FIGURES l-7. A terminal cylindrical portion 24" of an ink tube is shown encased in the plastice barrel 16, 16 of FIG- URES l-7. Prior to assembly, the terminal cylindrical portion 24" has been partially sheared at a point beyond the ink level in a manner such as to deform the :area adjacent the shear 26 and create a barbed portion 28.

As will be obvious to one skilled in the art, a compressive shear should be used at an angle such that the barb 28 points toward the point or to the left as viewed in FIGURE 8. When assembled, the plastic barrel 16' can be slid easily over the barb 28 which will tend to leave a sharp score on the interior of the plastic. The deformity in the tube at the area of the shear maintains the barb 28 in contact with the barrel 16.

Should now the barrel 16 be moved to the right (as viewed in FIGURE 8) which would tend to disassemble the pen, the barb 28 merely imbeds itself more firmly in the barrel interior wall, strongly opposing the movement. Should the barrel 16' be twisted, the barb 28 and the resulting score tend to resist the twisting movement.

Thus, there has been shown a novel ballpoint pen which can be attached to provide a single writing instrument which can be used for producing writing of different colors, or in the alternative, may be used to provide an instrument for Writing in the same color at both ends and having agreater ink supply than a single ended instrument could provide since each pen has a greater "rink capacity than a single tube of the over-all length of the pen.

A pen according to the present invention, in addition, has greater internal structural strength than is possible by offsetting each ink tube from its point of assembly when assembling the ink tubes in parallel alignment, or, alternatively, by assembling the tubes in some diagonal fashion through the plastic barrel. Furthermore, the pen of the present invention lends itself readily to mass production techniques, both in the fabrication of the ink tubes and in the assembly of the entire pen. As may be seen, a single die may be used for forming all of the ink tubes, which can then be interlocked in a unitary doubleended pen assembly.

Thus, there has been shown a novel ballpoint-penassembly which can be adapted to provide a single writing instrument with two writing points of different colored inks or, a double pointed pen having the same color ink, but in a greater supply in the same size cylindrical barrel. Each ball point pen assembly has a greater ink capacity than can otherwise be provided were it not for the overlap. The finished pen assembly has greater internal rigidity than is possible by merely offsetting each tube from its point assemblyand assembling the pens with the ink tubes in parallel alignment. Alternatively, by providing a barb in each ink tube, the tubes can be firmly anchored in the plastic barrels, strongly resisting any attempts to either twist the barrels or separate them.

What is claimed is:

1. A double ended pen comprising:

a substantially rigid ink tube of cylindrical cross section and having a ballpoint assembly at one end and an offset portion of relatively flattened cross section and terminating in a cylindrical portion at the other end that is offset from the ballpoint assembly,

a second substantially rigid ink tube of cylindrical cross section and having a ballpoint assembly at one end and an offset portion of relatively flattened cross section terminating in a cylindrical portion at the other end that is offset from the ballpoint assembly,

said ink tubes being interengaged with the flattened portions of each cartridge positioned adjacent the terminal cylindrical portion of the other thereby to interlock,

and a barrel for tightly fastening said ink tubes together in said interlocked relation, the writing end of said ballpoint assemblies projecting beyond the opposite ends of the barrel.

2. In the pen of claim 1, the terminal cylindrical portion of each ink tube having a projecting barb to anchor in said barrel.

3. A double ended'pen comprising:

a pair of cartridges enclosed within a barrel,

each cartridge having a substantially rigid ink tube of cylindrical cross section with a ballpoint assembly at one end and an offset portion of relatively flattened cross section and terminating in a cylindrical portion at the other end that is offset from the ballpoint assembly,

said cartridges being interengaged with the flattened portion of each cartridge adjacent the terminal cy in- References citerl in the file of this patent drical portion or" the other thereby to interlock, UNITED STATES PATENTS and a barrel for tightly fastening said mterengaged cara no tridges together in said interlocked relation, 272,932 A i 2/ J said barrel including a pair of cylindrical sections 5 613,453 Llppmcmt 1898 abutted end to end and being press fitted over said $2,594 Kfifldau 51911 cartridges along a substantial portion of their length, 2 1 Nelson May 2 1919 the writing ends of said ballpoint assemblies project- 4505307 Wgber APR 1950 ing beyond the opposite ends of the barrel. FORE GN PATENTS 4. In the en of claim 3, the terminal cyhndncal por- 10 373,700 Italy Aug 1, 1939 tion of each cartridge having a projecting banb to anchor a in said barrel 802 29 Germany Feb. 5, 1951 

1. A DOUBLE ENDED PEN COMPRISING: A SUBSTANTIALLY RIGID INK TUBE OF CYLINDRICAL CROSS SECTION AND HAVING A BALLPOINT ASSEMBLY AT ONE END AND AN OFFSET PORTION OF RELATIVELY FLATTENED CROSS SECTION AND TERMINATING IN A CYLINDRICAL PORTION AT THE OTHER END THAT IS OFFSET FROM THE BALLPOINT ASSEMBLY, A SECOND SUBSTANTIALLY RIGID INK TUBE OF CYLINDRICAL CROSS SECTION AND HAVING A BALLPOINT ASSEMBLY AT ONE END AND AN OFFSET PORTION OF RELATIVELY FLATTENED CROSS SECTION TERMINATING IN A CYLINDRICAL PORTION AT THE OTHER END THAT IS OFFSET FROM THE BALLPOINT ASSEMBLY, SAID INK TUBES BEING INTERENGAGED WITH THE FLATTENED PORTIONS OF EACH CARTRIDGE POSITIONED ADJACENT THE TERMINAL CYLINDRICAL PORTION OF THE OTHER THEREBY TO INTERLOCK, AND A BARREL FOR TIGHTLY FASTENING SAID INK TUBES TOGETHER IN SAID INTERLOCKED RELATION, THE WRITING END OF SAID BALLPOINT ASSEMBLIES PROJECTING BEYOND THE OPPOSITE ENDS OF THE BARREL. 